The distractor previewing effect (DPE) is observed in oddball search tasks and refers to delayed responses to targets that have been associated with distractor status on an immediately preceding target-absent trial. A recent eye-movement study of the DPE (Caddigan & Lleras, 2008) showed that when participants were asked to make a saccade to a color-oddball target, saccade latency was slower and saccades were less accurate when the target color in the current trial was the same as the color of the distractors in the preceding target-absent trial. These changes in eye-movement behavior can be due to changes in bottom-up signals or to top-down modulations about what to do with those signals (or to both). In terms of bottom-up changes, attention may be less likely to be attracted to the target because its salience has decreased, thereby slowing the rate of evidence accumulation towards an attention movement in its direction. Alternatively, top-down modulations may also be at play: heightening attentional decision thresholds would require longer accumulation periods before an attention movement is executed. Here we modeled the eye-movement data using a computational model based on a leaky, competing accumulator in which both target and distractors have their own parameters of signal strengths and decision thresholds. Goodness-of-fit tests showed that changes to signal strengths alone (evidence accumulation) cannot account for the observed data. Only when changes to the decision thresholds were modeled (heightening thresholds to recently seen distractor colors and simultaneously lowering thresholds to other features) was the model able to accurately predict the saccade latency and landing accuracy data. Our results clearly support a top-down interpretation of the DPE (see Lleras et al., 2008) and further specifies how attentional biases are instantiated between trials: as modulations of decision thresholds responsible for triggering attention (and eye movements) toward specific features in the display.